1. Field of the Invention
The present invention relates to a printing apparatus, a control method of the printing apparatus, and a storage medium.
2. Description of the Related Art
Conventionally, there have been proposed a copying machine and a printer including a tab sheet insertion mode capable of inserting tab sheets (also referred to as “index sheets”) at predetermined positions in an output stack constituted by sheets having a normal size to generate a document containing headlines and divided chapters. Tab sheets used in such printing are prepared as one set constituted by a combination of a predetermined number of tab sheets. For example, for a five tab sheet set, one set is constituted by five tab sheets.
However, when five tab sheets are placed though only two positions are specified as tab insertion positions, three of them become surplus sheets. Therefore, a problem arises that, if a next document set or a next job starts to be printed without removing the surplus tab sheets, the next print output has tab positions different from those in the previous print output.
However, it is bothersome for a user to remove these surplus tab sheets in advance and then reset tab sheets for the next printing. As an attempt to improve this situation, Japanese Patent Application Laid-Open No. 2003-40517 discusses a technique of automatically discharging surplus tab sheets, for example, at a break between printing of document sets or jobs to thereby enable printing of tab sheets from the head thereof in the next set of documents or the next job.
However, this technique may require additional operations for switching the sheet feed stages and switching between two-sided and one-side modes when the printing apparatus discharges surplus tab sheets.
For example, as illustrated in FIG. 10, it is assumed that surplus tab sheets are discharged after completion of printing of one set of documents 1001. In this case, plain sheets are fed after the sheet feed stage is switched at timing A. Then, after three plain sheets are fed, the sheet feed stage is again switched to discharge the surplus tab sheet. Then, after the surplus tab sheets are fed, the sheet feed state is further switched at timing B to feed plain sheets for a next set of documents.
When the sheet feed stages are switched in this way, some time period is to be taken between conveyance of plain sheets and conveyance of a tab sheet, for changing the sheet conveyance path and preventing occurrence of a jam. Therefore, an increase in the number of times of switching the sheet feed stages results in prolonged time until completion of the printing operation by the secured time, thereby reducing the productivity of the printing apparatus.
Further, when plain sheets are printed in the two-sided printing mode, a discharge of surplus tab sheets requires switching the conveyance path used in two-side printing to the conveyance path used in one-sided printing. As a result, the interval time of conveyance between sheets is increased caused by the switching, thereby reducing the productivity of the printing apparatus.
In this way, switching of the sheet feed stages and switching between two-sided and one-side modes lead to a deterioration in the productivity of the printing apparatus. Especially, when a sheet before or after a discharge of a surplus tab sheet is not a tab sheet, it becomes necessary to switch the sheet feed stages and switch the printing mode between two-sided and one-side modes, resulting in the deterioration in productivity of the printing apparatus.